1. Field of the Invention
The present invention relates to phosphites, and more particularly related to neoalkyl phenyl phosphites.
2. Description of the Related Art
Neoalkyl phenyl phosphites are known, see Dever et al U.S. Pat. No. 3,714,302 which is incorporated herein by reference. Dever et al teaches neoalkyl phenyl phosphites of the formula: ##STR2## wherein R and R' are independently lower alkyl groups and X, Y and Z are independently selected from the group consisting of --H and alkyl groups of from 1 to 5 carbon atoms, providing that the sum of the carbon atoms in X, Y and Z does not exceed 5, may be simply and economically produced by the reaction of a neoglycol with PCl.sub.3 in the absence of a catalyst, HCl acceptor and solvent to produce a crude product of the formula: ##STR3## wherein R and R' are defined above, followed by reaction with phenol or a compound of the formula: ##STR4## in which X, Y and Z are defined above. The desired product of Dever et al. may be recovered by distillation.
Suitable glycols are listed and include 2-ethyl-2-butyl-1,3 propane diol among others.
Dever et al. U.S. Pat. No. 3,714,302 clearly teaches away from compounds wherein X and Z are both alkyl groups such that they create stearic hinderance. Specifically note col. 3, lines 63 to 65 thereof wherein it states that the proviso that the sum of X, Y and Z does not exceed 5 excludes such phenols as 2,6-di-tertiarybutyl phenols from consideration because of stearic hinderance problems.
Dever et al U.S. Pat. No. 3,467,733 discloses compounds of the formula: ##STR5## wherein R is independently selected from the group consisting of hydrogen, alkyl of 1 to 6 carbon atoms, and halogen; X is a monovalent radical of the formula: ##STR6## wherein R.sup.2 independently selected from the group consisting of hydrogen, alkyl of 1 to 12 carbon atoms and halogen, and R.sup.3 is independently selected from the group consisting of alkyl of 1 to 12 carbon atoms and halogen, and sets forth in claim 7 a phosphite of the formula: ##STR7##
Many of these phosphites can, however, experience thermal stability problems, hydrolytic stability problems, and/or ultraviolet light discoloration problems.
Consequently, there is a need for a neoalkyl aryl phosphite exhibiting improved ultraviolet and hydrolytic stability.